DE-OS No. 27 27 244, FIGS. 20/21, discloses a rubber motor mount. This motor mount has a circular partition fabricated from a rubber-elastic material which has a centrally arranged circular choke opening. The partition is spaced a radial distance from a cutout contained in the bottom plate. The passage opening between the working space and the equalization space caused by this radial spacing has a considerably larger cross-section than the choke opening. At small vibration amplitudes, substantially no hydraulic liquid passes through the choke opening and the passage opening. At large vibration amplitudes, the partition rests against one of the two stop grids and forms a seal. The initial good insulating effect with respect to introduced vibrations then becomes a damping effect which is desired, e.g., for the suppression of the sputtering motions of a mounted internal-combustion engine. However, the development of considerable noise by the rubber bearing must be tolerated.
In some regions, the partition has a greater thickness than in other regions. Contact of the partition against the grids results from the independent mobility of the partial regions. The resulting stress on the rubber-elastic partition can lead to its early distruction. The desired goal of improving the comfort of a passenger in, e.g., an automobile is achieved only to a small degree. An increasing pressure rise in one of the two spaces leads to a stepwise reduction of the choke coss-section available.
French Pat. No. 11 12 598 discloses a partition fabricated from an elastic material which is fixed in a piston and which has cutouts which expand when large amounts of liquid pass through. The cutouts are circular and the partition rests against support grids on both sides. Both measures cause a strong progressive damping behavior. The partition cannot assume the task of sealing.